Two stroke stinks less

Colorado State University engineering students have designed a snowmobile that decreases pollution by more than 99%, cuts fuel consumption 35% and reduces noise to conversational levels.

A typical snowmobile can produce as much air pollution as 100 cars. However, Colorado State University engineering students have designed a snowmobile that decreases pollution by more than 99%, cuts fuel consumption 35%, reduces noise to conversational levels and matches the power of today’s top-performing commercial machines.

The engine design has the potential to dramatically reduce the environmental impact of snowmobiling and decrease pollution in developing countries.

‘Our design should appeal to the environmentalist and the snowmobiler,’ said Jessica Rupp, one of the student engineers. ‘This snowmobile demonstrates a phenomenal reduction in environmental impact while improving overall performance.’

The Colorado State student team has been selected to compete against 16 other schools in the Third Annual Clean Snowmobile Challenge March 23-30 in Jackson Hole, WY. The international competition challenges teams to design, build and operate snowmobiles that reduce emissions and noise while matching or improving the performance of machines sold on the market.

‘Most commercial snowmobiles use two-stroke engines that are highly polluting,’ said Colorado State team captain Tim Bauer. ‘Our team has developed new technology to dramatically reduce pollution from two-stroke engines.’

Bryan Willson, associate professor of mechanical engineering and team adviser, said the technology developed at Colorado State has important prospective applications beyond snowmobiling. In particular, the engine design could provide means to reduce pollution in Third World countries.

‘A major part of the air pollution in Asian and African cities is generated by vehicles with traditional two-stroke engines such as those used in snowmobiles. Our new two-stroke technology has the potential to reduce pollution throughout the developing world,’ said Willson. ‘In fact, we have already been contacted by agencies in India and West Africa to discuss how this type of engine can be used to reduce pollution and increase the quality of life in these countries.’

Additionally, Colorado State representatives have been invited to visit with US government officials in Washington, DC, in April to discuss potential applications of this two-stroke technology for use in developing countries.

To reduce the pollution in a two-stroke engine, the Colorado State team began by installing a new type of fuel injection system. They partnered with the Orbital Engine Corporation of Australia and adapted the company’s advanced direct-injection technology to use in snowmobiles. Among other modifications, this required the team to build new high-performance cylinder heads.

The Colorado State student team also added a catalytic converter to oxidise any pollutants that escape the engine and developed a new muffler to reduce noise without robbing power. Even the snowmobile’s ride is more comfortable due to a high-performance suspension and an ergonomically redesigned seat and handlebar.

Sponsored by the Society of Automotive Engineers, the Clean Snowmobile Challenge was created to generate new ideas and technology to address growing concerns about exhaust and noise pollutants from off-road engines. Competition events include emission testing, acceleration, hill climb, cold start, handling, noise measurement and fuel economy.